PET imaging with the Tau radioligand AV-1451 was introduced into the BLSA study in 2016. In combination with PET amyloid imaging and MRI measures, these studies will provide information on the preclinical stages of Alzheimer's Disease. As of August 22, 2018, 79 BLSA participants have been enrolled in the study and more than 30 have had at least one repeated study. A customized analysis pipeline has been developed with refined MRI-based regions using the MUSE analysis for structural MRI region of interest definition. Images are acquired on a High Resolution Research Tomograph for PET brain imaging and transferred to the Laboratory of Behavioral Neuroscience for analysis. Preliminary analysis of the first 60 images show the expected finding of greater Tau deposition in individuals with positive amyloid PET scans. In addition, associations of extracerebral off-target binding with age have been demonstrated. Analysis of additional images is underway and longitudinal repeats, as well as new enrollment, continue.